Well-treating tool



Sept.l '4"flh943` .m w. FRAcK '2329557 WELL Tnx-:mina mor.. luna@ Apri;so.' i941 A T 'TORNEi/S.

Patente-d Sept. 7, 1943 Dow .Chemical Company Midland,Mich.'a

corporation of Michigan Application April 30, 1941,.

2 claims. (o1. 16e-2o) This invention relates to an improvement in awell treating tool adapted to deliver one or more high velocity streamsor .jets of acid solution into a well bore against the face oftheformation, well casing, or other parts of the Well.

, In treating wellswherein a tool is employed to direct a series of highvelocity streams of acid .against various portions of the well bore, -itoftentimes happens that it is desirable to seal the orices through whichthe acid issues during the period the tool is being positioned at thedesired location in the well bore. Placing a seal over the orifices isdesirable in order to eliminate the possibility of sand, or mud enteringthe tool through the orifices and exerting a plugging action by becominglodged in the small passageways through which the fluid passes. It isalsodesirable to prevent entry of fluid 'into a treating tool of thistype since any uid which enters the tool must be forced therefromthrough the ysmall orices therein, and as a result more time is requiredto complete a treatment. Such sealing means should, however, be readilyremovable after the treating tool has been positioned at vthe desiredlocation in the `Well bore.

It is, therefore, the principal object of ths'invention to provide anacidY treating tool having sealing .covers for the orifices throughwhich the acid solution isto be ejected, said covers being characterizedby being readily removable after the acidizing tool has been positionedin the well Y bore at the desired location.

xshown issuing from the tool I and impinging against theface of theformation at5. f

In the more detailed View of Fig. 2 the housing 6 of the acidizing toolis shown connected atits upper end to a swage nipple 1 by means ofcoupling or collar 8. The reduced vend of nipple 'I is threaded forconnection to the conduit 3 whichv may suitably be the Well tubing. Atintervals the housing is provided Withplug members r9 which are attachedto the housing as by welding. The plug members 9 are internally threadedfor 1 threaded engagement with the orice members I through which theacid issues into the well bore.

In the enlarged detailed view of Fig. 3 an orifice member I0 is shownwith a small orice or port I I centrally located therein. The orice I Iis counterbored at the outlet so as to form anenlarged recess I2 intowhich a dome-shaped readily acid-soluble metal disk I3 is pressed to actas a seal for the orifice.

Other objects and advantages will be apparent as the description of theinvention proceeds'.

The invention will be more readily understood from the followingdescription taken in connection with the accompanying drawing wherein:

Fig. l is a somewhat diagrammatical elevational vieW of a well boreshowing the tool positioned adjacent a section ofthe formation it is Ydesired to treat.

n adapted to cover the orifice.

Fig. is a cross-sectional view taken along lines 5,-5 of Fig. 4.

As shown in Fig. 1, the acidizmgtom |v is suspended in the well bore 2by means of a suitable conduit 3. High velocity streams of acid 4 areThe dome-like shape of the readily acid-soluble metal disk will be morereadily appreciated with i and upon coming intoV contact with thereadily acid-soluble sealing disks will rapidly dissolve them so thatthe acid solution will have ready access to the Well bore. Pressure willthen be applied to the acid to force it from the tool in high velocitystreams or jets. The pressure employed may vary quite widely as from afew hundred upto 3,000 pounds per square inch.

The acid solution to employ will, of course, depend upon the use forwhich it is intended. In generaLwhen treating a producing formation orbringing about the disintegration of cement, hydrochloric acid or amixture of hydrochloric acid and hydroiiuoric acidv will be employed. y

The readily acid-soluble metal sealing disks are most suitably made ofmagnesium metal. The term magnesium used herein and in the appendedclaims is intended to include the magnesium of commerce which containssmall amounts of impurities such as iron, copper, and the like as Wellas' alloys of magnesium in which 'this metal is the predominantconstituent. Mag- '2,329,157 Y "Y I nesium is very readily soluble inmost acids and is very rapidly dissolved by both uninhibited andinhibited hydrochloric acid.

The sealing disks employed for the purpose at hand may vary quite Widelyin thickness. Generally illustrative of a suitable thickness is from 11gto 1A; of an inch. It has been found desirable t to form the disks sothat theyl will have avdomelike shape schislisiiliustraedfisince .largerarea will be 'r'rp'sed' to the action Yof the acid,

assuring more immediate and complete removalr A.

" housing into the Well bore, said plug members lhavingccunterboredrecesses about the orifices,

of the sealing covers.

I claim:

1.v In a. Well treating tool vadapted yto deliver am I K high velocitystream of acid to'lthe'vv'eli'fbcrte, the combination which includesahhusin'g' adapted'to.

be connected to the well tubing, plug members attached to the housinghavlgoribes therenffl 5 plug members in sealing relation.

2. In a well treating tool adapted to deliver a high velocity stream ofyacid to a Well bore, the combination which includes av conduit, ahousing aidaptefdto"bedconnectdto 'the "conduit, plug 1o membersattached to saidhousing having orifices p therein through which acid mayissue from the and dome-shaped magnesium metal disks engag- 'lngithcounter-bored recesses in the plug mem'- ersfin' 'sealing feiation.MORRIS W. FRACK.

